Ethanolic extracts of the plant Verbascum thapsus produce relaxation of the isolated guinea-pig trachea. In light of the potential clinical value of new and novel drugs for used in pulmonary disorders, we are proposing to extract and test the pharmacologically active substance(s) in plant. The chemical work involves extraction and purification of active ingredients, structural elucidation, structural modification, synthesis and a general work-up on the chemicals present in the plant. The pharmacological work involves analysis of the active constituents on guinea-pig trachea and right and left atria in order to determine selectivity and mechanism of action. Relative pulmonary vs. cardiovascular activity is determined in vivo in guinea pigs prepared to record changes in pulmonary pressure and blood pressure and electro-cardiogram.